perf test: Stat output per thread of just the parent process

Per-thread mode requires either system-wide (-a), a pid (-p) or a tid
(-t).

The stat output tests were using system-wide mode but this is racy when
threads are starting and exiting - something that happens a lot when
running the tests in parallel (perf test -p).

Avoid the race conditions by using pid mode with the pid of the parent
process.

Signed-off-by: Ian Rogers <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Christian Brauner <[email protected]>
Cc: Disha Goel <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: K Prateek Nayak <[email protected]>
Cc: Kajol Jain <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Song Liu <[email protected]>
Cc: Tim Chen <[email protected]>
Cc: Yicong Yang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

2 files changed, 2 insertions, 2 deletions

diff --git a/tools/perf/tests/shell/lib/stat_output.sh b/tools/perf/tests/shell/lib/stat_output.sh
index c81d6a9f7983..9a176ceae4a3 100644
--- a/tools/perf/tests/shell/lib/stat_output.sh
+++ b/tools/perf/tests/shell/lib/stat_output.sh
@@ -79,7 +79,7 @@ check_per_thread()
 		echo "[Skip] paranoid and not root"
 		return
 	fi
-	perf stat --per-thread -a $2 true
+	perf stat --per-thread -p $$ $2 true
 	commachecker --per-thread
 	echo "[Success]"
 }
diff --git a/tools/perf/tests/shell/stat+json_output.sh b/tools/perf/tests/shell/stat+json_output.sh
index 2b9c6212dffc..6b630d33c328 100755
--- a/tools/perf/tests/shell/stat+json_output.sh
+++ b/tools/perf/tests/shell/stat+json_output.sh
@@ -105,7 +105,7 @@ check_per_thread()
 		echo "[Skip] paranoia and not root"
 		return
 	fi
-	perf stat -j --per-thread -a -o "${stat_output}" true
+	perf stat -j --per-thread -p $$ -o "${stat_output}" true
 	$PYTHON $pythonchecker --per-thread --file "${stat_output}"
 	echo "[Success]"
 }